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V F Iamshchikov

Publications and source records attributed to V F Iamshchikov.

4 recordsLinked to original sources
PubMed1989

[Nucleotide sequence of the genome and complete amino acid sequence of a polyprotein of the tick-borne encephalitis virus].

We have cloned and sequenced RNA encoding all virion and nonstructural proteins of tick-borne encephalitis virus (TBEV). Its length is 10,477 bases with a single open reading frame (nucleotides 127-10,363) encoding 3412 amino acids. The 5'- and 3'-noncoding regions have stem- and- loop structure. The polyprotein precursor is proteolytically cleaved, apparently, by a mechanism resembling that proposed for the expression of polyproteins of other flaviviruses, such as yellow fever, West Nile and Kunjin viruses. The deduced TBEV gene order is 5'-C-preM (M)-E-NS1-NS2A-NS2B-NS3-NS4A-NS4B-NS5++ +-3'. The genome and the polyprotein of TBEV and other flaviviruses appears to be structurally similar, although these flaviviruses are transmitted to and from their vertebrate hosts by different carriers, such as ticks or mosquitoes. Analysis of sequence homologies of polyproteins of flaviviruses suggests that TBEV is more closely related to yellow fever virus than to other serological subgroups of flaviviruses (West Nile or Dengue viruses). The hydrophobic profiles of the flaviviruses are highly conservative. Nonstructural proteins NS2A, NS2B, NS4A and NS4B are extremely hydrophobic, suggesting that they are likely to be associated with cellular membranes. Proteins E, NS1, NS3 and NS5 are the most conservative and may be involved in general enzymatic activities related to viral replication and virion assembly.

Amino Acid Sequence↗
PubMed1986

[Nucleotide sequence of the genome region of the tick-borne encephalitis virus coding for structural virion proteins].

RNA of a flavivirus-tick-borne encephalitis virus (strain Sofjin) was subjected to reverse transcription and the DNA copy was transformed into double-stranded DNA by action of E. coli DNA-polymerase I (Klenow's fragment). This DNA was annealed with pBR322 plasmid. The recombinant plasmids were cloned in E. coli K802. The nucleotide sequence of the inserts of the clones coding for region of structural proteins C, pre-M, E and nonstructural protein ns1 was determined by the Maxam-Gilbert method. The nucleotide sequence of these regions is translatable into an amino acid sequence of proteins without interruption. The amino acid sequences of proteins and nucleotide sequence of genome of the tick-borne encephalitis virus are extensively homologous to that found for the flaviviruses Yellow Fever and West Nile.

Base Sequence↗
PubMed1985

[A plasmid vector with temperature-controlled gene expression].

A 169 b.p. fragment including the bla gene promoter p3 has been removed from pBR327 plasmid, and the deleted plasmid used for cloning the TaqI/BglII-fragment of the lambda c1857ind- DNA containing promoter pR and gene cI to obtain plasmid pCE119. Cells containing pCE119 produced a high level of beta-lactamase at 42 degrees C, the yield at 42 degrees C being 100 times higher than at 32 degrees C. For cloning and functional assays a pCEZ12 plasmid was constructed, in which promoter pR and repressor cI of lambda phage control the expression of the semi-synthetic beta-galactosidase gene. Yield of beta-galactosidase produced by pCEZ12 at 42 degrees C was ca. 300 times higher than at 32 degrees C.

Bacteriophage lambda↗